PHP中的OO麻烦（或任何非持久性环境）

Question

Unless you count QBASIC back when I was a kid, I learned to program in the object oriented paradigm a half-decade ago in university, so I understand how it works. I have difficulty, however, implementing it in my large, database-driven PHP applications, because everything is re-initialized on each page load. The only true persistence is the database, but pulling all the data from the database and reconstructing all the objects on every page load sounds like a lot of overhead for not much benefit, as I'll just have to do it all over again on next page load.

Additionally, I run into these sorts of problems when I try to re-factor an application (third attempt now) to OO:

---

A class called "Person" exists, and it contains a variety of properties. One of the extensions of that class, "Player", contains a "parent" property, of the type "Player". Initially, none of the players start with any parents, so they would all be initialized with that field as NULL. Over time, however, parents would be added to the Players properties, and would reference other Player objects that already exist.

In PHP, however, it's inevitable that I would have to rebuild the class structure with Players already having parents. In such a case, if I instantiate a Player who has as a parent a Player that hasn't been instantiated yet - I have a problem.

---

Is it necessary to reduce the scope of OO programming when dealing with PHP?

Answer 1

Items not being created by means of parents is indeed something that is tricky. You could do something like, ID referencing and build a PlayerManager that does the linking for you. By means of RUID's (Runtime Unique ID's). But of course, you would like to have the parents be created first.

So when creating something like an OO structure of your database, which I would encourage if you want to do some extra manipulations on it besides printing. It is doable to create a player from your DB and then, if it has a parent, create the parent as you would do normally. When arriving at the parent in your while-loop. You can just say, no it is already created. Use a Player-manager class for this, which holds your Players. So it can check if Players (and thus parents) are already there.

So you get a bit of a different way of walking through your DB, instead of just doing it linear.

As for: is it necessary to do so. I actually don't know that much about it myself. It seems, as far as I've seen on the web, that PHP classes are mostly used to created one object that can do smart things (like a DOMDocument).

But do you really have to convert your DB table to objects? It depends on your type of application. If printing is what you want, it doesn't seem logical. If some big manipulation with a lot of calls to the objects (or normally to the table), I maybe would like to see a nice OO programmed structure.